The invention concerns a device for limiting the amplitude of the relative movement of two elements of a civil engineering structure or of a building and for absorbing the deformation energy of this structure when the latter is subjected to an accidental stress, such as an earthquake, an exceptional wind, an explosion, an impact, etc. The invention also relates to civil engineering structures or buildings comprising such a device.
There already exist devices based on the same principle as that of the invention, namely the plastic deformation of a bar guided via its support on a curved surface which guarantees a major length of the bar is plasticized whilst controlling the deformations. Devices of this type are described in the document FR 2 756 581 in the name of the applicant, and incorporated herein by reference for all purposes.
The device of the invention can be placed in the structure when the latter is in the course of being constructed or at a subsequent stage with the aim of strengthening the structure.
The object of the invention is to improve known devices so as to provide an extremely simple device to be embodied and able to mass produce.
Apart for its substantial reduction of the production costs, another objective of the invention is to provide a device easy to use including in existing structures.
To this effect, the device of the invention comprises: at least one portion able to undergo a plastic deformation at the time of the relative movement of the two elements of said structure, means for guiding the plastic deformation of the portion able to undergo a plastic deformation, the portion able to undergo a plastic deformation and the guiding means forming a single piece element.
Thus, the invention provides a device embodied in a single piece which resolves the problem of positioning the various portions of the device in relation to one another and simplifies the production method.
According to the invention, the portion able to undergo a plastic deformation includes at lease one bar, preferably with a rectangular section linked to the means for guiding the plastic deformation at the level of one of its extremities, and the means for guiding the plastic deformation include at least one curving template defining at lease one curved surface on which the portion, able to undergo a plastic deformation during said deformation folds.
The invention also concerns a device including several identical superimposed single piece elements.
The device may also include at least one support element fixed to at least one template and having one portion of its surface adjacent to at least one bar, said support element being intended to limit tilting of the device during deformation of said device.
According to a first embodiment, the device of the invention includes a plurality of bars placed approximately parallel to one another inside a given plane between two approximately parallel straight lines. The extremities of each of the bars which are aligned on one first straight line are linked to a first curing template and the extremities of each of the bars, which are aligned on the second straight line, are linked to a second curving template. The two templates are situated inside said plane approximately perpendicular to said bars and each defining a curved surface on both sides of each of the bars.
The invention also concerns a portico structure defining approximately elementary meshes and including at least this device. This structure comprises four bars placed in the form of a cross, each bar being fixed at one of its extremities at one angle of said mesh, two adjacent bars being fixed at the other of their extremities to a first template of said device, the other two bars being fixed at the other of their extremities to the second template of said device.
According to a second embodiment, the device of the invention includes four bars placed crosswise inside a given plane and approximately perpendicular to one another, four curving templates placed crosswise inside said plane approximately symmetrically, each of the templates being positioned between two bars, said templates each defining curved surfaces; so that one curved surface is placed on both sides of the bars.
The invention also concerns a portico structure defining approximately rectangular elementary meshes and including at lest this device. This structure comprises eight bars placed so that two bars are fixed by one of their extremities at each angle of said mesh, two bars fixed at two adjacent angles are linked via their other extremity to a given bar of said device.
According to a third embodiment, the device of the invention includes one bar linked at each of its extremities to a curving template, each of the templates defining two curved surfaces placed on both sides of the bar.
This device is intended to be placed inside a structure comprising lintels and to be fixed approximately horizontally on these lintels.
According to a fourth embodiment, the device includes inside a given plane two aligned bars and linked to each other via one of their extremities, two arms placed perpendicularly to the bars at the level of the common extremity of said bars so as to form a cross, two curving templates placed on both sides of the two bars at the level of the common extremity of said two bars, each template defining a curved surface for each of the two bars.
The invention also concerns a portico structure including approximately horizontal girders and approximately vertical poles and including at least this device positioned at the level of the intersection between the girders and poles, the bars of the device being fixed approximately horizontally on the girders and the arms being fixed approximately vertically on the poles.
According to a fifth embodiment, the extremity of the bar not linked to the guiding means has a rounded shape or is fitted with a joint, the device being intended to be placed inside a civil engineering structure including at least two portions between which seismic isolators are placed. According to this embodiment, the guiding means are secured to a first portion of said structure and the extremity of the bar not linked to the guiding means slides in a slide secured to a second portion of said structure.
Finally, the invention concerns a civil engineering structure including at least two portions and at least one device according to the second or third embodiment, said device being placed so that the central portion of the device situated towards the common extremity of the bars is linked to a support device fixed at one portion of said structure, the extremity of each of the arms and/or bars not linked to the guiding means being able to slide in a slide secured to another portion of said structure.
Other technical advantages of the present disclosure will be readily apparent to one skilled in the art from the following Figures, descriptions, and claims. Various embodiments of the invention obtain only a subset of the advantages set forth. No one advantage is critical to the invention.